Analysis of astigmatic keratotomy.

Eighty-two keratotomy procedures were performed for both idiopathic and postsurgical astigmatism or myopic astigmatism and analyzed for efficacy using vector and linear regression analysis. Delta keratometry values (delta K) were computed for each case as delta K in the desired axis of effect using vector analysis. Six different procedures were compared including both intersecting and nonintersecting trapezoidal keratotomy, relaxing incisions with compression sutures, T cuts with radial keratotomy, T cuts alone, and RK with elliptical optical zones. Our results showed that the greatest shifts occurred in the trapezoidal groups, whereas the most predictable effects occurred in the relaxing incision/compression suture group. Astigmatic keratotomy is capable of producing large shifts in corneal astigmatism; however, the accuracy of these procedures remains highly variable.